N1's upper stages were designed to function standalone as lower-capability carriers, just like Saturn IVB / Saturn IB. A few more test flights and most probably USSR would have had N1-base lineup to replace R-7 and Proton and have 100-ton class heavy booster. However, Chelomei pushed his UDMH-fueled UR plan which resulted in the Proton, and Glushko wanted OKB-1 for himself.